J. Julien
University of Nantes
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Featured researches published by J. Julien.
Physics Letters B | 1991
J. Julien; D. Lebrun; A. Mougeot; P. de Saintignon; N. Alamanos; Y. Cassagnou; C. Le Brun; J.F. Lecolley; R. Legrain; G. Perrin
Abstract The cross section for K+ meson production in collisions of 36Ar ions on a 48Ti target has been measured at an incident energy of 92 MeV per nucleon. A description of the experimental set-up is given. Twelve events attributed to monoenergetic muons following the decay of stopped kaons have been identified. From these events, one infers a production cross section of 240 pb. Data are briefly discussed.
Nuclear Physics | 1988
B. Erazmus; C. Guet; R. McGrath; M.G. Saint-Laurent; Y Schutz; J.L. Ciffre; M. Boloré; Y. Cassagnou; H. Dabrowski; M. Hisleur; J. Julien; R. Legrain; C. Le Brun; J.F. Lecolley; M. Louvel
Abstract Positive pions and protons emitted at 90° were measured in coincidence with two fission fragments in the reaction 16 O + 232 Th at 95 MeV/nucleon. The linear momentum transfer distribution has been determined from the folding angle between the fragments. The average momentum transfer is 2.5 GeV/ c ± 0.2 GeV/ c for a pionic reaction. An analysis in terms of impact parameter distributions leads to the conclusion that subthreshold pion production requires a large overlap of projectile and target density profiles.
Nuclear Physics | 1995
F. R. Lecolley; N. Alamanos; L. Bianchi; Y. Cassagnou; H. Dabrowski; B. Erazmus; J. Julien; P. Hameau; D. Lebrun; C. Le Brun; J.F. Lecolley; R. Legrain; A. Mougeot; G. Perrin; P. de Saintignon; J.L. Sida; J.P. Wieleczko
Abstract The cross sections for K + meson production in collisions of 36 Ar on 12 C, nat Ti and 181 Ta at an incident energy of 92 MeV per nucleon have been measured. A description of the set-up and of the method is given ; it is based on measurement of the muon decay of the positive kaon. At such a low incident energy the K + production seems to be more sensitive to the available energy in the center of mass of the nucleus-nucleus system than to the coulomb corrected incident energy normalized to the production threshold in a free nucleon-nucleon process.
European Physical Journal A | 1994
J. Julien; M. Boloré; J. Gosset; J. M. Hisleur; A. Mougeot; G. S. Papparlado; B. Saghai; G. Sanouillet; D. Ardouin; H. Dabrowski; B. Erazmus; C. Lebrun; V. Bellini; L. Sperduto; C. Cerutti; S. Leray; D. Lebrun; P. de Saintignon; T. Johansson; K. Kilian; L. Bimbot
The observation of an enhancement in the production of low energy pions in the Cu(p, π+)X reaction is confirmed. The width of the bump is about 5 MeV around 350 MeV. A similar enhancement appears at 330 MeV for C(p, π+)X but the width has not been measured. An attempt to observe this behaviour in Cu(p, π∘)X is described. From the data one cannot conclude about the existence of a structure around 350 MeV proton energy. The lack of resolution in theπ∘ spectrometer may have washed out the small effect expected fromπ+ measurements.
Physics Letters B | 1989
D. Lebrun; J. Chauvin; D. Rebreyend; G. Perrin; P. de Saintignon; Ph. Martin; M. Buenerd; C. Le Brun; J.F. Lecolley; Y. Cassagnou; J. Julien; R. Legrain
Abstract Low momentum pion production is measured at an angle of 0° in 16O induced reactions. Strong Coulomb effects on the ratios π − π + are observed. Charge distributions of reaction products are extracted. Pions are produced by an intermediate system whose charge and velocity are given in agreement with the participant zone predicted in a simple geometrical participant-spectator picture. Effects due to projectile fragments are also observed, and are dominant in light mass systems.
European Physical Journal A | 1988
J. Julien; M. Boloré; H. Dabrowski; J. M. Hisleur; V. Bellini; A. S. Figuera; R. Fonte; A. Insolia; G. F. Palama; Giuseppe Russo; M. L. Sperduto; J. Chauvin; P. de Saintignon; D. Lebrun; D. Rebreyend
Inclusive production of neutral pions has been studied in16O +27Al,197Au reactions at 38 MeV/u and20Ne +27Al reaction at 200 MeV/u. A setup of 10 Pb glass Cherenkov detector telescopes was used to detect the twoγ rays from theπ0 decay.
European Physical Journal A | 1990
D. Lebrun; J. Chauvin; J. Julien; C. Lebrun; J.F. Lecolley; G. Perrin; D. Rebreyend; P. de Saintignon
Negative pion production cross-sections are measured at 38, 65 and 93 MeV per nucleon in O + Al reaction. Rough estimations of the total cross sections are given and compared to previous neutral pion data. Double differential cross sections at 93 and 65 MeV/u show enhancement for pions with velocity close to the beam. At variance no effect is observed at 38 MeV, where π− and π0 distributions are identical. Fewπ+ detected at 38 MeV support this result. This indicates that at the lowest incident energy nearly the whole projectile participates in the production reaction.
European Physical Journal A | 1989
J. Julien; V. Bellini; Y. Cassagnou; C. Cerruti; J. M. Hisleur; R. Legrain; B. Lucas
AbstractA new experiment was carried out at Modane (Laboratoire Souterrain de Modane, France) to determine the ration
European Physical Journal A | 1988
C. Cerruti; J. M. Hisleur; J. Julien; R. Legrain; Y. Cassagnou; M. Ribrag
Physical Review C | 1999
R. Legrain; J.F. Lecolley; F. R. Lecolley; N. Alamanos; L. Bianchi; Y. Cassagnou; H. Dabrowski; B. Erazmus; J. Julien; D. Lebrun; Ch. Le Brun; A. Mougeot; P. Hameau; G. Perrin; P. de Saintignon; J.L. Sida; J.P. Wieleczko
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